I made a really dumb mistake at the end of my kolsch brew and put the yeast into the wort when it was still at about 90 degrees fahrenheit. That was only a few hours ago, but I'm concerned I may have killed the yeast. Hopefully, by morning there will be bubbles coming out of the airlock, but if there aren't any, whats my next step? Also, if there are bubbles, could there be any bad effects on the beer?

Any activity yet? Hopefully the yeast will recover, but the beer might not be as clean as you might hope for a Kölsch. You probably want to get the beer down in the low 60s. If the yeast doesn't take off by tonight, you might want to pitch some fresh yeast.

Pitching at high temperatures can lead to off flavors, like high levels of esters and diacetyl. You can hope that the yeast kicks in and cleans up most of these compound before the beer is finished.

I was very happy to see lots of bubbles coming out of the airlock this morning. The wort is 68 degrees now. Hopefully, the yeast will clean up anything bad and that I will have learned a lesson about paying attention to temperature without any consequences.

You might want to try and lower the temperature a little bit more if you can. I ferment my Koelsch at 60-62F to try and keep it clean tasting. Also, leaving it a few extra days in primary, after the fermentation seems done, may help to clean it up. I made the mistake of moving a Koelsch to my cellar to cold condition a little too early, once. It took a good while for the acetaldehyde levels to get down to something I was happy with.